


Dark Equations

by sunalso



Category: Agents of S.H.I.E.L.D. (TV)
Genre: Alternate Universe- Fated Mates, F/M, HEA, Smut, Valkyries, Vampires, immortals after dark verse, valkyrie Jemma Simmons, vampire leo fitz
Language: English
Status: In-Progress
Published: 2020-11-15
Updated: 2020-11-14
Packaged: 2021-03-10 04:06:43
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,448
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27567964
Author URL: https://archiveofourown.org/users/sunalso/pseuds/sunalso
Summary: AU. Jemma is a valkyrie, Fitz is a vampire. They should be enemies, but fate has other plans for them. Set in Kresley Cole's Immortals After Dark universe.Beta'd by Gort
Relationships: Leo Fitz/Jemma Simmons
Comments: 10
Kudos: 47





	Dark Equations

**Author's Note:**

> _a/n: This has been a comfort fic for me as things get incredibly difficult in IRL. Updated when I can. I hope you enjoy! This is set in the Immortals After Dark universe, which is a series of paranormal romance novels written by Kresley Cole. I love these books and they were very instrumental to me wanting to write and tell stories. I still swear the beginning of A Hunger Like No Other is one of the most fantastic things I've ever read. The basics are that there are immortal creatures (vampires, valkyries, werewolves, demons, etc.) that are divided into factions and are at war. They also have fated mates. There's an IAD wiki if you need it!_

The bars were magically reinforced.

Jemma poked at them listlessly. Why did the bloody vampires have to have an actual medieval castle with a real dungeon in it? Besides her freedom, she wanted clean sheets and room service, not a pile of straw on the floor. It was an insult.

Everyone knew Valkyries adored the finer things in life.

The stiff stems rustled as she toed them. It wasn’t even exceptionally nice straw.

Her sisters would come for her, and as far as Vampires went, it was better to be with these Forebearers than with the kind that drank first and didn’t bother to ask questions later, but Jemma had been busy when she’d been so rudely abducted. It’d taken her two years to get to this point in her experiment with apricot fungi and she didn’t fancy starting over because she missed the window to collect the data. Being immortal did not mean she had infinite patience.

Pacing, she tried to figure out what the leeches would want, and how long it would take Bobbi to figure out where Jemma had been taken. Drat, why had she insisted on going into NOLA on today of all days? A sale at her favorite lab supply shop hadn’t really made it a necessary trip. She could have purchased all the glassware she could ever want at three times the price and never blinked at the total.

Jemma pressed her palms to the edges of her jaw, trying to quell the tightness that made the muscles ache.

Think, she had to think. It was what she was good at. Jemma the Studious. Her name did not evoke fear the way her sisters’ did, though it was hardly Jemma’s fault. She could wield a bow with deadly precision, as well as tell you the math behind every shot. Sometimes she worked the problems out after a training session just for fun, even if biology and chemistry were her first passions.

Nïx the Ever-Knowing had told Jemma that her brain was her strongest asset hundreds of years ago. She’d leaned over Jemma’s shoulder when Jemma had been absorbed in working out mathematical descriptions using the new technique of Calculus. Nïx had traced a finger over the numbers, then petted Jemma’s hair. “Ah yes,” Nïx had murmured. “Your faithful husband is math.” Then she’d wandered off before Jemma could figure out any questions to ask.

Most of the coven had simply took it to mean that Jemma would never be mated, and after decades of teasing, she’d started believing that interpretation as well. Wedded to her work.

Which meant that the blasted Forebearers kidnapping her, probably with plans to interrogate her, were pointless. Everybody knew Jemma kept her nose shoved in a textbook, not battleplans. She had nothing to tell them. It was going to be a long night, possibly with torture, which she was so not into. She preferred not to force her immortal body to do any more healing than needed.

She also got teased about being careful. Which was a load of rubbish. Not every single being in the Lore needed to be a scary uber-warrior.

Jemma sat on the flagstones, avoiding the questionable-quality straw, and raked her hands through her hair.

Something dropped from her head to ping on the floor.

She picked up a slightly bent hairpin, one that’d been keeping her wavy hair up and out of her face while she’d been shopping. A simple look to go with the simple summer dress she had on.

What luck that she hadn’t put her hair up in a ponytail.

Several seconds of frantic finger combing yielded two more.

Jemma grinned. She’d heard all about how no force or magic could break the bars, but there was still a big lock that’d needed a key. Getting to her knees, she shuffled over to the cell’s door. The first pin slipped in easily, but as she moved it around to examine the inner mechanism, she groaned.

Of course it wasn’t a standard lock. She was going to need all three hairpins and a good bit of luck to get it open. She bit her lip in concentration. Who’d ever designed this lock had to be brilliant, but Jemma had no doubt she was cleverer.

#

The lightning had stopped, which was a blessing. Fitz made a mental note to add more lightning rods to the castle. He was always the only one worried about things like weather, since he was the one who lived in the bloody tower. He’d started with a single room in the spire because nobody else wanted it, then took over a whole floor, and now, after several centuries, the entire tower belonged to him.

Well, technically it belonging to his king, but so long as Fitz repaired anything he was asked to, and kept on top of current research to provide the Forebearers with up to date technology as well as Lore-specific inventions, then Fitz was allowed to have all the space he needed in the castle’s high west tower. Along with all the blood in the fridge he required.

His king might have turned him for how Fitz had tried, and ultimately failed, to use his brain to keep him alive on the battlefield, but Kristoff had seen Fitz’s true worth and treated him well. Or at least Fitz couldn’t find much to complain about.

He even had a few mates that stopped by for chats on the regular.

It was a good life, or as much of a life as a vampire could have, and he didn’t need a stray bolt from a damned Valkyrie mucking it up.

Fitz turned away from the window, which he kept open to the night air when it wasn’t storming or daylight, and sat down at his worktable. The sturdy, hand made table dominated his bedroom, his actual bed a simple mattress in the corner. He slept irregularly, and since no Bride had blooded him, he didn’t need to worry about satisfying his nonexistent sexual urges.

Once upon a time he’d been obsessed with finding the one other member of the Lore that was meant to spend all eternity with him, who’d make his heart beat once more and his cock stand to attention. He’d almost forgotten what an erection felt like, the centuries old memory dim and distant. Not that he’d done much with that part of himself when he’d been alive, anyway. He’d been too young and too focused on staying alive to tumble any of the willing village lasses or have more than a quick pull under the covers when he’d both been alone and not worried he’d die in the morning.

Those things hadn’t coincided nearly often enough. It figured that one of his biggest regrets was that he hadn’t wanked enough.

As a vampire, he’d traveled for ten years in the 1850s, searching, imagining, dreaming, and wanting his mate. All for naught. It’d been a long shot anyway, fate had a sick sense of humor and immortals could wait millennia to trip over their other half. Fitz had eventually decided that if it was meant to be, then they’d find each other. No need to galivant around like a ninny when there was work to be done.

He turned on his desk lamp, grinning at the bright light that flooded the taser he was building to take down werewolves. Not an easy task, those lykea buggers were tough, but he had an idea on how to deliver a high enough dose of electricity to knock their nerves into a few seconds of disarray. It’d be all a vampire needed to gain the upper hand.

Fitz adored that he had been around for the adoption of widespread electricity, and computers. Especially computers that didn’t take up an entire floor of his tower and needed neatly ordered punch cards. He still hadn’t forgiven Hunter for that time he’d knocked into Fitz and scattered the cards he’d been carrying everywhere.

Slipping a pair of magnifiers on, Fitz picked up tweezers to get started on the next phase of the circuit board he was building.

He didn’t know how long he’d been dealing with the fiddly little bits when he heard light steps on the stairs of his tower.

Fitz heaved a gusty sigh. “Can I help you?” he asked, not looking up from his circuit. Somebody always wanted something.

“Oh!” gasped a soft voice he didn’t recognize. “I didn’t see you. No. I’m good. Stay there.”

He looked up and saw nothing but a chestnut blur.

Ah, right, magnifiers.

Pushing them up on top of his head, Fitz blinked at the vision standing in his bedroom. Little pointed ears poked through the heavy waves of her dark hair, her fingers were tipped in claws, and the cutest, tinest fang poked at her bottom lip. Valkyrie, but a lovely one. Who was near his window, but who also had one of his notebooks in her hand. Caramel colored eyes met his, then dipped back to the writing in the book.

“Uh, you got out?” he asked, rubbing at his cheek. Terrific, Fitz, he chided himself. Obviously she knew she’d escaped. It’d been a daft idea to nab a Valkyrie for information on the Lore in the first place. Though he would love to know how she’d defeated the cell’s wards.

“Nope,” she chippered. “I’m a figment of your imagination.” She flipped through a couple of pages while he desperately tried to remember what designs were in that particular notebook. Green cover…it might be wind or solar panel related projects. Green was for green energy ideas.

She leaned a sweet hip against the stone windowsill and kept reading.

The dull memory of arousal ghosted through the back of his mind, because this Valkyrie was gorgeous, with her cute nose, sprinkling of freckles, and delicious looking tits.

She tilted her head to the side, emphasizing the steady beating of her pulse in her throat. His fangs ached to sink into her milky skin and draw that sweetness--

Shite.

The single most important covenant of the Forebearers were that they did not drink blood from the living. They _forebeared_ for pete’s sake.

“Why are you in my bloody tower?” he snapped, wanting her gone so he could forget she existed.

“Stop eyeing my throat, leech.” She licked a finger and flipped a page. “And the rest of me. You’re not blooded.”

Fitz groaned and put his hands on his hips. “Just answer the question.” Were all Valkyries this annoying? How had nobody wiped them out yet?

She fixed him with a glare. “Yours is the only open window in this very dark, very moist, castle. I’m sure my sisters will be here soon to get me. I’m waiting on them.”

“And how did you escape? Seduce someone?” Something tightened in his chest at the thought of her moaning and writhing under another. Which made no sense. She’d been here all of ten minutes at the most and was already driving him barmy.

“Picked the lock.”

His mouth fell open. “You did not.”

The Valkyrie closed the book and tossed it onto the corner of his desk. She crossed her arms. “Complicated design. I’m guessing it was yours?”

“Yes, yes, but…how?”

She raised a brow.

“Fuck, I’ve been telling everyone I need to do a redesign, make them electronic. But does anyone ever listen to me?”

The other brow went up. “It really is quite ingenious, how they work.”

“Thank you.”

“I don’t think anyone besides me would have worked it out.”

He shook his head. “And you are?” He really, really needed to know.

“Jemma. It’s nice to meet you. Too bad we’re enemies or I’d sit and have tea and a chat with you about some of those designs. I think you need to consider a few things with your solar panels.”

He blinked at her. “I don’t drink tea.”

“I don’t either, but I like how it smells.”

“Oh, uh, I’m Leopold Fitz. Just call me Fitz.”

“Fitz,” she said, like she was trying out the word. The sound was more melodic on her lips than he’d ever imagined his name could be. “I don’t think I needed to know your name, but so far I haven’t had to worry about killing you. Don’t start being terrible now. Alright?”

“I wasn’t planning on it,” he muttered. “What if you’re not whisked off in a moment?” He rather found it rude for her to tell him that they could have a conversation about solar panels, and maybe she’d want to discuss electricity and werewolves before she jaunted off back to wherever Valkyries came from.

“I could totally kill—”

She was cut off by a reverberating boom. The entire castle shuddered. Dust shaken from the roof flittered to the floor.

Jemma yipped and rushed across the room, tossing herself at him. He caught her, somehow, wrapping his arms around her and pulling her tight against him. She was warm and smelled like sunshine and summer.

“What was that?” she asked from where here face was pressed against his shoulder.

Unable to stop himself, he stroked the heavy, glossy strands of her hair. Jemma radiated warmth; hot enough Fitz was amazed he didn’t catch fire. “Just the porticus lowering.” Unfortunately. “The guards know you’re missing.”

She didn’t let go of him. 

A second harsh boom sounded. A third. The force shook him.

His eyes darted about. Those detonations hadn’t been the porticus. He dragged Jemma tighter against him. He might not be the fiercest warrior by far, but he’d protect her.

Another explosion ripped through him. A fourth.

An ache settled low down in his belly. The pain wasn’t one he was familiar with.

He sucked in a breath. It felt different. Cool, sweet, full of Jemma’s summer scent.

“Fitz,” she said, her searing palm cupping his cheeks. Her face had paled. “Bloody hell,” she whispered. “I ran to you, and…your heart.”

His heart?

She pushed herself a step back, making him growl. Jemma did not belong a step back from him.

Her gaze lowered and she sucked in a breath. “Oh my,” she said, the words a throaty purr.

Fitz looked down. The front of his trousers were tented out. _Oh_. That would explain the insistent throbbing in his groin.

“Oh,” he managed. “Oh, hell.”

The explosions, which were coming closer together, weren’t a threat. His heart was beating.

She’d blooded him. After so long, he’d been blooded in his lab of all places.

Lust, purse and desperate, flooded through him.

Jemma was his mate.

Three centuries of longing and Fitz had at last found his Bride.


End file.
